MOCAP
Motion Capture is simplest form it is the recording of the motion of an object by a computer using a series of sensors. As a process it is the planning, recording and integration of that data – It’s the people in Lycra suits covered in shiny ping-pong balls - markers.
In simple terms motion capture systems can capture the motion of anything you can attach a sensor to. Attaching the sensor is the easy bit, applying the data to your model convincingly is the tricky part.
All motion capture systems collect some sort of data from the object the sensors are attached to. Optical systems calculate the relative position of each marker. Inertial systems measure the acceleration and rotation of each sensor.
In it’s raw form motion capture is simply a set of values for each sensor at a specific time, so you need a way to transfer this data on to your object inside a computer. If you think of it like a puppet system, you need the strings to transfer the movements of the performer on to the puppet in the computer.Some capture systems come with their own software for doing this –Vicon’s Blade, Motion Analysis’ Cortex, and Xsens MVN software.
There are also a number of third party software solutions like Autodesk MotionBuilder and PeelSolve. Some facilities have also developed their own software solutions like Giant Studios.
The actual capturing of the motion or performance is only the middle part of the process though. Before you start capturing you need to decide what you’re going to capture and how you’re going to capture it.Once the capturing is done you’ll need to map the data to your character and integrate it in to your pipeline.
Sounds simple enough? Except within each one of those steps there are a number of other tasks to contend with like
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Creating move lists
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Arranging shoots
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Rigging characters
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Capturing the data
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Cleaning up the data
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Mapping the data to your character
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Editing the data
The markers or sensors are placed in precise locations on the body to capture it’s movements. They needs to stay fixed to those locations to accurately record the movement of the performer. If the performer wears loose fitting clothing the markers will move around independently of their body. You would be capturing the movement of the clothing not the movement of the performer. Although there is still a small amount of movement with the Lycra suits it’s a lot less than a sweatshirt and jeans. So for now it’s black Lycra suits – at least the cameras cant see you, for that it’s even worse!
PIPELINE
Capture Process Steps
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Planning
– Deciding what to capture -
Shooting
– Getting the performances you want -
Processing
– Keeping (making) the data faithful to the original performance
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AnimationandDelivery
– Making the CG character move like the original performer
Planning a Mocap Shoot
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Understand your goals – What’s important and how do I get it?
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What information should I prepare?– Shot list
– Mocap pipeline technical spec
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What arrangements need to be made?
– Talent/ Props
• Target skeleton/character topology • Target control structure
• Gross proportional differences
• Target software platform
• Number of characters/performers • Props
• Frames per second
– Look for motion performance
– Get props out of the way
• Data management is key
• Why?
– All the data in the world is useless if I don’t know where it is and what it is.
What to Store
Performer Name
Shoot day and date
Source and target file names Capture and delivery frame rates Delivery format...
Calibrate cameras, prepare the stage, put markers on the floor defining range of movements, set up character definition, redady....go!!
It’s Working!
PREVIZ and the ENEMY at the scene
in progress...
CHARACTER MODELING AND TESTS
CLOTH TEST
FACE EXPRESSIONS TEST
Really quick character modelling. Good to work with zBrush again. My idea is to do a set extension, some test with camera taking combined with a CG character /Dobby - the guy down there/ A lot of experiments with the lights, set optimisation, rendering....Still a lot of problems -/like shadow of the statue in the bottom the scene. Thats because I ve tried to "save time"
and I did not alfa chanel but just a flat plane for the BGR image. Whatever - I know where the problem is. I did a test to convert 3d scans to 3d objects and I put it on the scene - lion mother, and two male statues. Thats it for now - still I ll try to get maximum of this scene but ...still in progress....